1. Field of the Invention
The present invention relates, generally, to transportation systems and processes, and in particular embodiments, to ground-based transportation systems and processes employing magnetically levitated vehicles for transportation of freight or passengers. Certain embodiments are configured for relatively low-cost and energy efficient implementations.
2. Background of the Disclosure
Transportation of freight and passengers can be necessary in the modern economic society. During the current and previous centuries significant advances have been made with respect to the speed and efficiency of transportation systems. Such advances have been driven, at least in part, by economic demand. Indeed, high-speed transportation of freight and passengers has long been recognized as having significant economic value. This is evidenced by the widespread use of air transportation and increasing use of high-speed rail in both freight and passenger markets.
Conventional high-speed rail systems can require mechanical contact between wheels and rail, giving rise to vibration, noise, wear, and frictional losses of energy. Air transportation requires the high costs of pilots, air traffic control systems, airports and an even larger expenditures of energy.
Past efforts to address some of those shortcomings have included efforts to develop magnetically levitated train systems. Prototypes of such systems have been constructed that would require costly infrastructure in the form of heavy and precise track systems or expensive superconducting magnets. In some prior systems, massive trains have been proposed, requiring massive, expensive infrastructure. In addition, prior systems have employed relatively complex geometries, due to a perceived necessity to provide horizontal surfaces to create levitation forces and vertical surfaces to create lateral forces. Moreover, since electromagnets can only generate attractive forces, some proposed systems have included vehicles configured with awkward and heavy structures that reach underneath an iron rail to create lift.
A common feature of many such prior designs is that the vehicle structure wraps partially around the track structure or the track structure wraps partially around the vehicle structure. Such structures can be complex and massive, as they support high loads applied to cantilevered substructures. An indication of the complexity of these systems is that there is no single plane that separates the vehicle magnetic components from the track magnetic components. This follows from the use of both vertical and horizontal magnetic gaps in such designs. These structures are not only large and expensive, but also make track switching slow and cumbersome, compromising the potential for speed and convenience offered by maglev systems.
A railroad switch, or turnout, is a mechanical installation enabling trains to be guided from one line of rail tracks to another. In a typical installation, rail track “A” divides into two tracks, “B” and “C”. At the bifurcation point, a switch contains a pair of linked tapering rails (point blades) that can be moved laterally into one of two positions, determining whether a train coming from “A” will be led towards “B” or towards “C”. Likewise, in order to allow maglev vehicles to be directed along varying transportation routes, some type of mechanism must be provided that is capable of switching the vehicle from one guideway to another. In some maglev systems, such as the German Transrapid and the Japanese Railway MLX-01, this mechanism involves physically displacing a large guideway segment in order to redirect the maglev train.
U.S. Pat. No. 3,964,398 (titled “Magnetic-suspension vehicle system having switch tracks”) to Breitling, describes a magnetic-suspension vehicle system in which a vehicle is displaceable along a track provided with armature rails which cooperate with electromagnets carried by the vehicle to suspend the latter from the track. Switch locations provided along the track and the rails in these regions are designed to allow crossover of the electromagnetic arrangement on each side of the vehicle between main and auxiliary rails. The main and auxiliary rails are shaped to prevent mutual interference at the crossover points or their junction sites at a common side of the vehicle.
U.S. Pat. No. 5,517,924 (titled “Double row loop-coil configuration for high-speed electrodynamic maglev suspension, guidance, propulsion and guideway directional switching”) to He, et al. describes a stabilization and propulsion system comprising a series of loop-coils arranged in parallel rows wherein two rows combine to form one of two magnetic rails. Levitation and lateral stability are provided when the induced field in the magnetic rails interacts with superconducting magnets mounted on the magnetic levitation (maglev) vehicle. The loop-coils forming the magnetic rails have specified dimensions and a specified number of turns and by constructing differently these specifications, for one rail with respect to the other, the angle of tilt of the vehicle can be controlled during directional switching. Propulsion is provided by the interaction of a traveling magnetic wave associated with the coils forming the rails and the superconducting magnets on the vehicle.
U.S. Pat. No. 5,865,123 (titled “Electromagnetic induction suspension and horizontal switching system for a vehicle on a planar guideway”) to Powell, et al. describes an electromagnetic induction suspension and horizontal switching system for a vehicle on a substantially planar guideway that provides vertical lift and stability and lateral stability for a vehicle, including pitch, yaw and roll stability. The suspension and stabilization system allows electronic, horizontal switching between multiple substantially planar guideways such as a mainline guideway and a secondary guideway, which may be accomplished at speeds over 300 m.p.h. Proximal to and within a switching area at the intersection of the mainline guideway and the secondary guideway, the respective lift and stability systems for each guideway coexist and may be switched on or off, depending on the path chosen for the vehicle.